Split drum for lift strap in ceiling lift

ABSTRACT

A patient lift system includes a lift housing, a base lift strap having a first end coupled to a lift housing and a second end coupled to a sling bar. The base lift strap is infection controlled. In one embodiment, a protective sleeve covers the base lift strap, wherein the protective sleeve has a first end and a second end. In another embodiment, the base lift strap is chemically treated to provide infection control.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalPatent Application No. 61/784,073, filed on Mar. 14, 2013, the contentsof which are herein incorporated by reference in their entirety.

FIELD

This disclosure relates to overhead patient lift systems.

BACKGROUND

Motorized overhead patient lift systems are known for use in connectionwith lift straps, sling bars and patient lift slings to lift andtransport patients for any number of reasons. The majority of suchmotorized overhead lift systems typically operate like a winch andusually include a lift motor, a cylindrical lift drum driven by the liftmotor, a housing for enclosing the motor and lift drum, and a lift strapaffixed at one end within the lift drum for lifting or lowering apatient when the drum is rotated and the strap is respectfully eitherwound up on the lift drum or paid out from the lift drum. The lift drumof a typical overhead lift system is generally a solid, one-piececylinder having a central axis of rotation, a cylindrical outer worksurface around which the lift strap is wrapped, circular end flanges ateach end of the drum, and a strap retention slot for retaining an end oflift strap therein.

However, over time, lift straps wear out from excessive use as well asdeterioration caused by the cleaning and disinfecting, or sanitization,process used to prevent bacterial growth on the lift straps. Forexample, the majority of hospitals that use overhead patient liftsystems require that the lift strap be cleaned and disinfected daily orbetween patient uses. The cleaning and disinfecting, or sanitization,process required by hospitals typically involves the application ofchlorinated bleach to the textile lift strap, which lift strap istypically a woven polyester lift strap similar to those used forautomobile seat belts. When the chlorinated bleach on the lift strapdries, solid crystals of chlorine are left embedded in the woven fibersof the textile lift strap. Over time, these chlorine crystals build upand deteriorate, or break down, the lift strap's woven fibers, thusreducing the maximum tensile strength of the lift strap and reducing theamount of the active load that can safely be carried by the lift strap.

Accordingly, lift straps often need to be replaced after a certainamount of time or upon signs of excessive wear from use and cleaning.When replacement of the lift strap is necessary, it is often adifficult, tedious, and time consuming process to do so. Most overheadlifts hang from guiderails mounted to the ceiling and are located at aheight well above the reach of most individuals. Thus, to replace thelift strap safely and avoid the need for prolonged work while standingon a ladder or working overhead, the entire lift itself must usually beremoved from the guide rail system so that replacement of the lift strapcan be performed while the lift is on a work table or the like. Due tothe weight of the overhead lift, and the need for it to be held securelyin the overhead rail system anchored to the ceiling when in use, suchremoval of the overhead lift is not particularly easy and presents thechance to inadvertently drop the lift from a fairly high height.

Also, because the lift drum is fixed within the outer housing, replacinga lift strap usually involves the removal of at least one end of theouter housing (if not the entire outer housing). It also usuallyrequires removal of the strap guide slot that is fastened to the bottomside of the housing and through which the strap safely enters or exitsthe interior of the outer housing. Replacement of the lift strap alsorequires removal the fixed end of the lift strap from its affixedposition inside of the lift drum. Often times, this process may furtherrequire the removal of numerous screws, fasteners, and extraneous parts,the disconnection of various electrical connections, such as limitingswitches or other safety features, the accounting for all removed parts,and the recalling of the proper assembly order of the aforementionedparts so that the lift can be correctly reassembled.

Accordingly, there is a need for a lift system that provides a quickerand easier way to gain access to the lift drum for lift strapreplacement, as well as an easier way to remove and replace the liftstrap, without needing to go through such a tedious and time consumingprocess as is currently required to replace such a lift strap for anoverhead lift.

In addition, there is a need to either (1) provide an improved infectioncontrol lift strap, such that it is easier to clean and will not besubject to premature wear caused by the cleaning process, or (2) betterprevent bacteria and other contaminants from reaching the lift strap,and therefore, reducing the frequency with which such harsh cleaning andsanitization procedures need to be performed. By achieving either ofthese goals, the usable life of the lift strap can be extended beyondthat which is currently experienced.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in detail below with reference to theattached drawing figures, wherein:

FIG. 1 is an isometric view of an embodiment of a split lift drum of thepresent disclosure, showing the strap-lock slider in an extendedposition and a new lift strap being installed therein.

FIG. 2 is an isometric view of the embodiment of the split lift drum ofFIG. 1, showing the strap-lock slider in an extended position from thedrum body and the replacement lift strap installed therein.

FIG. 3 is an isometric view of the embodiment of the split lift drum ofFIG. 1, showing the strap-lock slider and installed lift strap in thefully mated and secured position within the drum body, ready for use inan overhead lift system.

FIG. 4 is a side view of the embodiment of the split lift drum of FIG.1.

FIG. 5 is an isometric cross-section view of the embodiment of the splitlift drum of FIG. 4, taken about the section line indicated in FIG. 4,showing the strap-lock slider and installed lift strap in the fullymated and secured position within the drum body.

FIG. 6 is an isometric cross-section detail view of FIG. 4, showing anembodiment of the lift strap locking bar installed in the strapretention recess in the strap-lock slider.

FIG. 7 is an isometric cross-section view of the embodiment of the splitlift drum of FIG. 4, taken about section line A-A in FIG. 4, showing thestrap-lock slider and installed lift strap in the extended position fromthe drum body, wherein the lift strap is accessible for replacement.

FIG. 8 is an isometric view of an embodiment of an overhead lift systemof the present disclosure utilizing a split lift drum as disclosedherein, and showing an embodiment of an access door in a bottom of thelift housing in a closed position.

FIG. 9 is an isometric view of an embodiment of an overhead lift systemof the present disclosure, and showing an embodiment of an infectioncontrol protective sleeve installed over the lift strap of the overheadlift system, secured at the top end of the sleeve to a lift housing andat the bottom end of the sleeve to a lift strap fastener.

FIG. 10 is an isometric cross section view of an infection controlcoated lift strap of the present disclosure.

FIG. 11 is an isometric view of the embodiment of the lift strap lockingbar as shown in FIG. 6.

FIG. 12 is an isometric view of the embodiment of the lift strap lockingbar of FIG. 11 secured to the end of a lift strap.

FIG. 13 is an isometric view of an embodiment of an overhead lift systemof the present disclosure utilizing a split lift drum as disclosedherein, and showing an embodiment of an access door in the lift housingin an opened position to provide access to the split lift drum.

DETAILED DESCRIPTION

Various embodiments now will be described more fully hereinafter withreference to the accompanying drawings, which form a part hereof, andwhich show, by way of illustration, specific embodiments. However, thisinvention may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the invention to thoseskilled in the art. The following detailed description is not to betaken in a limiting sense.

Throughout the specification and claims, the following terms take themeanings explicitly associated herein, unless the context clearlydictates otherwise. The phrase “in one embodiment” does not necessarilyrefer to the same embodiment, although it may. Furthermore, the phrase“in another embodiment” does not necessarily refer to a differentembodiment, although it may. Thus, as described below, variousembodiments may be readily combined without departing from the scope orspirit of the present disclosure.

In addition, as used herein, the term “or” is an inclusive “or”operator, and is equivalent to the term “and/or,” unless the contextclearly dictates otherwise. The term “based on” is not exclusive andallows for being based on additional factors not described, unless thecontext clearly dictates otherwise. In addition, throughout thespecification, the meaning of “a,” “an,” and “the” include pluralreferences. The meaning of “in” includes “in” and “on.”

Referring to FIG. 1, an embodiment of a split lift drum, or split drum2, for use in winding up and paying out a lift strap in a ceilingmounted patient lift is shown. The split drum 2 comprises at least adrum body 4, a strap-lock slider 6 that is slidably engaged within thedrum body 4, and one or more fasteners 8 for affixing the strap-lockslider 6 in a fully seated position within the drum body 4.

Drum Body

Referring to FIGS. 1-4, the drum body 4 is generally shaped like acircular cylindrical spool, in that it has a circular cylindricalcentral barrel 10, end flanges 12 disposed at each of a first end 14 andsecond end 16 of the central barrel 10, a central axis of rotation 18,and a circular cylindrical outer work surface 20 disposed on theexterior of the central barrel 10, around which a lift strap 62 will bewrapped during use of the split drum 2. The outer diameter of each endflange 12 is larger than the outer diameter of the central barrel 10, soas to properly guide a lift strap around the work surface 20 of thecentral barrel 10 when the lift strap is being wound up on the splitdrum 2. The larger diameter end flanges 12 also serve to keep the liftstrap 62 centered on the work surface 20 between the end flanges 12 ofthe split drum 2 and prevent the lift strap 62 from sliding off of thesplit drum 2.

The drum body 4 also includes a slider channel 22 formed in the centralbarrel 10 of the drum body 4 to permit the strap-lock slider 6 to beslidably mated therein. The slider channel 22 is generally a radialchannel that is disposed transverse to the central axis 18 and definesat least one opening 24 in the exterior work surface 20 of the centralbarrel 10. The opening 24 defined in the work surface 20 by the sliderchannel 22 forms a break in the otherwise continuous cylindrical outerwork surface 20 of the central barrel.

Referring to FIG. 5, the pictured embodiment of the drum body 4 shows across section of the drum body 4 taken through section line A-A in FIG.4. Section line A-A is a section plane that is perpendicular to thecentral axis of rotation 18 and that sections through the slider channel22 formed in the central barrel 10. In FIG. 5, it can be seen that theslider channel 22 of this embodiment is generally in the shape of anupside down “T.” The “T” shape of the slider channel is formed by theperpendicular intersection of (1) a square-bottomed through-slot cutperpendicular to the rotational axis through a portion of the outer worksurface of the central barrel, the slot forming the top cross member ofthe “T” shaped channel, and (2) a rectangular through-hole passingthrough the axis of rotation in the central barrel that forms the mainleg of the “T” shape. In the depicted embodiment, the height of thecross member of the “T” shaped slider channel through the central barrelis approximately one-fourth of the width of the diameter of the centralbarrel, however in alternate embodiments, it may be of any number ofdifferent sizes.

A longitudinal centerline of the rectangular through-hole that forms themain leg of the “T” shape intersects the central axis of rotation 18 ofthe drum body 4. The longitudinal centerline of the rectangularthrough-hole also bisects the square bottomed through-slot that formsthe cross member of the “T.” The “T” shaped slider channel also definesa pair of drum stop-faces 26. These drum stop-faces 26 provide apositive stopping surface against which a pair of complimentary sliderstop faces on the strap-lock slider 6 will rest, when the strap-lockslider 6 is mated to a fully seated position in the slider channel 22 ofthe drum body 4.

While the above described embodiment discloses a “T” shaped sliderchannel 22, this disclosure should not be read to limit the sliderchannel to any specific shape. Rather, in alternate embodiments, theslider channel may take additional shapes, and/or be of alternatechannel types, without departing from the scope of this disclosure. Forexample, in an alternate embodiment the slider channel may be ablind-hole type channel having a single opening in the central barreland traveling a specific distance into the central barrel, where thechannel bottoms out within an interior of the central barrel. In stillanother alternate embodiment, the slider channel may be a through-holetype channel wherein the channel passes completely through the centralbarrel and defines a first opening on one side of the central barrel anda second opening on an opposite side of the central barrel.

In one embodiment, the slider channel 22 may have a square orrectangular cross-section when being viewed through the opening 24 ofthe slider channel formed in the work surface 20 of the central barrel10. In an alternate embodiment, the slider channel 22 may have acircular or oval cross-section when being viewed through the openingformed in the work surface 20 of the central barrel 10. In still furtheralternate embodiments, the slider channel 22 may take any such shapethat permits the strap-lock slider 6 to slidably be engaged or matedwithin the drum body 4.

Strap-Lock Slider

Referring to FIGS. 1-3, 5 and 7, the depicted embodiment of thestrap-lock slider 6 is a generally formed as an upside down “T” shapethat is complementary to the shape of the slider channel 22 in the drumbody 4. In this regard, the strap-lock slider 6 includes a longitudinalslider body 28 having a first end 30 and a second end 32. Disposed atthe first end of the slider body 28 are a pair of ears 34 that extendtherefrom, one each, on opposite sides of the slider body. The two ears34 on opposite sides of the slider body 28 form the cross member of the“T” shaped strap-lock slider 6. In this embodiment, the “T” shapedstrap-lock slider generally has a square or rectangular outer crosssection through the main leg of the “T” shape. However, as statedpreviously, in alternate embodiments, the cross section of thestrap-lock slider will have a shape that is complementary to the shapeof the slider channel in the drum body 4. Accordingly, should the sliderchannel in the drum body 4 be circular cylindrical in shape, then theslider body of the strap-lock slider will also be circular cylindricalin shape such that the strap-lock slider can be slidably mated into theslider channel in the drum body 4.

The opposing outer end faces 36, 38 of the first end 30 and second end32 of the strap-lock slider, including the outer surfaces of the earsdisposed at the first end 30, are convex cylindrical curved surfacesthat share a common central axis and have radii that are each equal tothe radius of the central barrel's outer work surface 20 in the drumbody 4. In this manner, when the strap-lock slider 6 is slidably matedto a fully seated position in the slider channel 22 of the drum body 4,the outer end faces 36, 38 at the first and second ends of thestrap-lock slider 6 will be flush with, and have the same curvature as,the cylindrical outer work surface 20 of the drum body 4, such that agenerally complete cylindrical outer work surface is created for thesplit lift drum 2.

Furthermore, each of the two ears 34 of the strap-lock slider 6 definesa slider stop face 40, which stop faces are generally located oppositeof the curved outer end face 36 at the first end 30 of the slider body28. The slider stop faces 40, as described above with respect to thedrum body 4, form a positive stop against which the drum stop-faces 26will mate when the strap-lock slider 6 is in a fully seated positionwithin the drum body 4.

In addition, disposed in the first end of the slider body is a strapretention recess 42 that runs parallel to the central axis of rotation18 of the drum body 4. In the depicted embodiment, the retention recessis a through-hole whose cross section has parallel sides andsemicircular ends. This through-hole is configured to permit acomplementary shaped strap locking bar secured to the end of a liftstrap 62 to be slidably mated therein. The retention recess 42 alsoincludes a thin strap-entry slot 44 cut through one sidewall thereofthat extends to and through the curved outer end face 36 at the firstend of the strap-lock slider 6. The retention recess 42 has asignificantly larger width than the strap-entry slot 44, which slot isgenerally just wider than the thickness of the lift strap 62. This thinslot 44 permits access from an interior of the retention recess 42 to anexterior of the slider body. When a strap locking pin is slid into theretention recess 42, the portion of the lift strap 62 extending from thelocking pin is slid through the strap-entry slot 44 in the slider body28, such that the end of lift strap 62 is secured into the strap-lockslider 6 while the remainder of the lift strap 62 protrudes through thestrap-entry slot 44 and is located external to the strap-lock slider 6.

While the prior embodiment disclosed a strap retention recess 42 of aparticular shape, it should be understood that in alternate embodimentsthe strap retention recess may have alternate cross-sectional shapes asneeded to compliment the shape of a strap locking pin at the end of thelift strap 62 that is to be retained therein.

Fasteners

Referring to FIGS. 1-3, 5, and 7, the split drum can further include oneor more fasteners 8 for retaining the strap-lock slider 6 in a fullyseated and refracted position within the drum body 4. In the embodimentdepicted in FIGS. 1-3, 5, and 7, the fasteners 8 are a pair ofcountersink screws 46 that are removeably mated through countersunk earholes 48 located in the ears 34 of the strap-lock slider 6, and whosethreaded shanks protrude from the slider stop-faces 40. The screws 46are screwed into complementary threaded holes 50 disposed in the drumstop-faces 26 of the drum body 4. The countersunk ear holes 48 andscrews 46 permit the strap-lock slider 6 to be locked in to the drumbody 4 in a fully seated position without having screw heads protrudingabove the curved outer work surface of the combined drum body andstrap-lock slider. While the above embodiment disclosed the use of screwtype fasteners, it should not be read to limit the type or number offasteners 8 that can be used to secure the strap-lock slider in aload-bearing, fully mated position within the drum body 4. In alternateembodiments, additional fastener types, such as ball-lock fasteners,shear pin fasteners, alternate threaded fasteners, bayonet typefasteners, and other similar, load-bearing fastener types, may beemployed to secure the strap-lock slider in a load-bearing, fully matedposition in the drum body 4.

In one embodiment, the strap-lock slider 6 may be fully slidablyremovable from the drum body 4 by simply removing or disengaging thefasteners 8. However, in such an embodiment, should those fasteners 8ever break while the lift strap 62 is under load and the strap iscompletely unwound from the work surface, the strap-lock slider 6 coulddisengage completely from the drum body and drop the load at the end ofthe lift strap 62 to the floor rather abruptly. Accordingly, alternateembodiments of the present disclosure provide a safety mechanism,whereby even if the fasteners 8 break or become disengaged, thestrap-lock slider 6 cannot be fully disengaged from the drum body 4.Accordingly, in an alternate embodiment, the strap-lock slider and drumbody 4 may be configured such that, when the fasteners 8 are disengagedfrom the strap-lock slider 6 and the drum body 4, the strap-lock slideris able to be slidably moved within the drum body 4, but cannot becompletely removed from the slider channel 22 of the drum body 4 withoutfirst removing a safety shaft inserted through both the drum body 4 andthe strap-lock slider 6. In this manner, the strap-lock slider 6 is atleast partially retained within the drum body 4 at all times, even whenthe fasteners 8 are disengaged.

Referring to FIG. 5, to create the safety mechanism and achieve thepartial slidable retention of the strap-lock slider 6 within the sliderchannel 22 of the drum body 4, a closed-end safety slot 52 is defined inthe strap-lock slider 6 and extends through opposing slider faces of thestrap-lock slider 6. The safety slot 52 is a longitudinal rectangularcavity having semicircular opposite ends, however, alternate safety slotshapes may be utilized as is appropriate. An axial hole 54 is alsodefined through the center of the drum body 6 such that it is concentricwith the axis of rotation 18. The axial hole 54 extends at least throughone side of the drum body up to, and into, the slider channel 22. Inalternate embodiments, the axial hole 54 may extend through the sliderchannel 22 and into a portion of, or completely through, the oppositeside of the drum body, such that a section of the axial hole 54 isdisposed in the drum body 4 on both sides of the slider channel.

The safety mechanism discussed above is created by the engagement of aload bearing axial shaft 56 through both of (1) the axial hole 54 in thedrum body and (2) the closed-end safety slot 52 in the strap-lock slider6. When the axial shaft is engaged through both of the drum body 4 andstrap-lock slider 6, the load bearing axial shaft 56 permits thestrap-lock slider 6 to be slidably movable within the slider channel 22about the length of the safety slot 52, but prevents the strap-lockslider 6 from being completely removable, due to the interferencebetween the axial shaft 56 and the closed end of the safety slot 52 thatfully surrounds the axial shaft 56. Accordingly, when the fasteners 8are disengaged, the strap-lock slider 6 may only be permitted to dropfrom a fully mated and operational position within the drum body 4, toan extended position within, but protruding from, the drum body 4. Whenthe strap-lock slider is in the extended position, the first end 30 ofthe strap-lock slider 6 is at least partially clear of the outer edgesof the end flanges 12 on the drum body 4 and the strap retention recess42 is now accessible. Once the strap retention recess 42 is accessible,the lift strap 62's locking bar, located at the end of the lift strap62, can be slidably removed from the strap retention recess 42 of thestrap-lock slider 6 in order to replace the lift strap 62.

The above disclosure of the safety mechanism, employing an axial shaftand complimentary slot in the slider, to prevent complete removal of thestrap-lock slider should not be read to limit the method or apparatusesby which the strap-lock slider is slidably retained within the drumbody, but prevented from complete removal, when the fasteners areremoved or disengaged. In alternate embodiments, no axial shaft may beneeded to achieve such a safety mechanism or the axial movement.

For example, in an alternate embodiment, the strap-lock slider may beslidably retained within the drum body by the use of a set oftoggle-type, spring loaded arms disposed in the drum body. The arms aresecured in pockets within the walls of the slider channel in the drumbody by hinge pins, and are biased to an extended position by torsionsprings. The arms fold about the spring loaded hinges and the endsthereof engage in an interference manner within complementary pocketsdisposed along the slider faces of the strap-lock slider when thefasteners are disengaged and the strap-lock slide is moved to anextended position from the drum body. The interference fit preventscomplete removal of the strap-lock slider from the drum body.Alternatively, the spring loaded arms may be located in pockets disposedin the spring lock slider and engage with complementary pockets in thewalls of the drum body.

Another alternate embodiment has a two piece drum body, wherein one ofthe end flanges of the drum body is a separate piece that is secured tothe drum body, and which forms one side wall of the slider channel. Uponremoval of the separate end flange, one sidewall of the slider channelis removed to reveal an offset “I” shaped slider channel, whereby theupper cross member of the “I” channel is taller than the lower crossmember of the “I” channel. A complementary “I” shaped strap-lock slideris mated into the slider channel through the open side of the sliderchannel that has been opened by the removal of the end flange. The endflange is again secured to the drum body closing up the otherwise openside of the slider channel. The top cross member of the “I” shapedstrap-lock slider is shorter than the height of the top cross member ofthe “I” shaped slider channel. The “I” shaped strap-lock slider is thusslidably retained within in the drum body, yet can slidably move suchthat the bottom of the strap-lock slider is extended from the drum body.The strap-lock slider can then be slidably moved to a fully seatedposition in the drum body and secured in place by fasteners, thuspreventing any sliding movement while the fasteners are engaged.

Emergency Brake

The lift system employing the split drum 2 may further optionallyinclude an emergency brake to prevent free rotation of the split drum 2in the unlikely event that the drive gearing of the split drum 2 becomesdisengaged from the gearing of the driving motor. If the lift systemsenses that the lift drum suddenly begins paying out the lift strap 62faster than a predetermined rate or that rotational speed of the splitdrum 2 exceeds a predetermined speed, the emergency brake automaticallyengages. The sensing of excessive speed may be done by an electronicsensor and/or programming in the controller circuitry of the liftsystem. Alternatively, the sensing can be performed by mechanical meanssuch as a centripetal drive, or rhombic drive, connected to the rotatingsplit drum, which drive acts as, or similar to, a speed governor.

In one embodiment as shown in FIG. 5, the emergency brake is a shear-pintype emergency brake, wherein one or more frame shear pins (notdepicted) located external to an end of the split drum automaticallyspring forward to mate with and engage into at least one of a set ofemergency brake shear holes 74 in the split drum. The shear holes 74each run parallel to the central rotational axis 18 of the split drum 2and the pins are only able to move in a direction parallel to the axisof rotation, such that when the pins engage the holes, the pins stop thesplit drum from rotating any further. This prevents the lift strap 62from being paid out any further and in turn prevents the load suspendedfrom the end of the lift strap 62 from dropping any further toward thefloor. However, in alternate embodiments, alternate emergency brakesystems can be employed without departing from the scope of the presentdisclosure.

Each of the drum body 4, strap-lock slider 6, fasteners 8, and loadbearing axial shaft 56 are made from steel, aluminum, other suchsuitable metal or metal alloy, polymer, co-polymer, or any combinationthereof, that has the needed strength, weight, and durabilitycharacteristics to handle the loads to which each such component will besubjected during use of the split drum 2 and the lift system of whichthe split drum 2 is a part.

Operation

Referring to FIGS. 1-3, 7, and 13, in operation, the split lift drum 2is operably connected to a lift motor, both of which are retained insidean outer lift housing 58 and are a part of the overhead lift. Theoverhead lift may be secured within an overhead rail system mounted tostructural components within the ceiling of a patient room, such thatthe lift is a moveable, overhead patient lift. The lift mayalternatively be affixed to a single anchor located in the ceiling, inwhich case it is not a moveable patient lift, rather a stationary lift.The lift motor rotationally drives the split lift drum 2 about the drumbody's central axis of rotation 18. In one embodiment, a radial bearingmay be employed to aid rotational movement of the split drum 2. Such aradial bearing has a rotational axis that is collinear with therotational axis of the drum body 4. In one embodiment, the first end ofthe drum body 4 includes gearing 60 that is either integral to oraffixed to the drum body 4 on an outer surface of the end flange 12. Thegearing is operatively coupled to complementary gearing that is eitherdirectly connected to, or driven by the lift motor. However, inalternate embodiments, worm gearing configurations, chain or beltdrives, or similar such driving mechanisms may be employed to drive thesplit lift drum.

An operator control is utilized to input commands for controllingoperation of the lift motor, and thereby the operation of the split liftdrum 2. The motor can be directed to drive the gearing 60 in a firstrotational direction, thereby winding up the lift strap 62 that extendstherefrom and thus raising the free end of the lift strap and anyonesuspended therefrom. The motor can also be directed to drive the gearing60 in a second rotational direction opposite the first rotationaldirection, thereby paying out the lift strap 62 from the split drum 2and lowering the free end of the lift strap and anyone suspendedtherefrom.

When it is necessary to replace the lift strap 62 in the overheadpatient lift, either due to damage/wear to the lift strap, routinemaintenance, or for any other reason, replacement is simplified by useof the split lift drum 2. To replace the lift strap 62 extending fromthe bottom side of the overhead lift, any active load is removed fromthe free hanging end of the lift strap 62 and the motor rotates thesplit lift drum 2 such that it pays out the full available length of thelift strap 62, leaving the strap extending radially outward from theouter work surface 20 of the split lift drum 2. With the lift strap 62fully unwound and extended from the split lift drum 2, the sliderchannel 22 and complementary strap-lock slider 6 are oriented verticallywith respect to the direction of sliding motion, such that they areplaced in the upside down “T” position. In such a position, once thefasteners 8 are disengaged, the strap-lock slider 6 is slidably moveableto an extended position from the drum body 4 in the downward verticaldirection. To gain access to the split drum 2, an access door 64,disposed in a bottom side of the lift housing 58 and surrounding theprotruding lift strap 62, is opened. Opening the access door 64 providesaccess to the fasteners 8 that secure the strap-lock slider 6 in thefully seated and secured position within the drum body 4 of the splitdrum 2. In one embodiment, the access door 64 in the bottom of the lifthousing 58 may be a single door hinged with respect to the remainder ofthe lift housing 58. In alternate embodiments, the access door 64 may bepair of hinged access doors, a removable snap-fit panel, a slidingpanel, a flexible sliding roll-up type retractable panel, or any othertype of cover for an access opening that provides selectable access tothe split drum 2 inside the lift housing 58.

With the access door 64 opened or removed from the lift housing 58, thefasteners 8 are exposed. The fasteners 8 are next removed or disengaged,as the case may be, to permit the strap-lock slider 6 to slidably dropvertically downward in relation to the drum body 4, to an extendedposition directed radially outward from the drum body 4. In the depictedembodiment, the fasteners 8 are a pair of screws 46 that are unscrewedand removed from the ears 34 of the strap lock slider 6. Once thestrap-lock slider 6 is in an extended position, the strap retentionrecess 42 is extended in a radial direction away from the axis ofrotation 18 such that it is located farther from the axis of rotation 18than the outer edge of the end flanges 12. Therefore, the slider'sretention recess 42 is clear of the end flanges 12 of the drum body 4,and a strap locking bar 66 affixed to the end of the lift strap 62 maybe slidably disengaged from within the strap retention recess 42 of thestrap-lock slider 6. In this manner, the lift strap 62 has been removedfrom the overhead lift for replacement.

With the old lift strap removed, a new lift strap 62 is installed bysliding the strap locking bar 66 secured to the end of the newreplacement lift strap into the retention recess 42 of the strap-lockslider 6 in a direction parallel to the central axis of rotation 18 ofthe split drum 2. In doing so, the portion of the lift strap 62extending from the locking bar 66 is also inserted into the strap-entryslot 44 in the slider 6 and extends outward and downward form thestrap-lock slider 6. Once the strap locking bar 66 is fully seatedwithin the strap retention recess 42, the strap-lock slider 6 may bepushed vertically upward such that it is retracted within the drum body4 and is again located in its fully seated position within the drum body4. In this position, the drum stop faces 26 are mated against, and flushwith, the slider stop faces 40, while the curved end faces 36, 38 of thestrap-lock slider 6 are flush, and in alignment, with the outer worksurface 20 of the drum body 4. This creates a continuous outer worksurface without any significant gaps therein. The fasteners 8 arere-engaged thereby securing the strap-lock slider in the fully seatedposition within the drum body 4. In the depicted embodiment of FIG. 1the fasteners 8 are a pair of screws 46 that are inserted through thecountersunk holes 48 in the ears 34 of the strap-lock slider 6 andscrewed into complementary threaded holes 50 in the drum body 2. Theaccess door 64 in the lift housing 58 is secured back in place, and themotor may drive the split drum 2 to rotate and wind up the extended liftstrap 62 around the outer work surface 20 of the split lift drum 2. Thelift strap has thus been replaced in a much more expedient manner ascompared to current lift systems and techniques, and the overhead liftis then ready for continued use.

Strap Locking Bar

Referring to FIGS. 5-7, 11, and 12, the strap locking bar 66 disposed atthe end of the lift strap 62 that secures the lift strap 62 within thestrap-locking slider 6 may be a single mandrel or pin, around which theend of the end of the lift strap 62 is tightly wrapped and secured backonto itself either by stitching or other similar securing mechanism. Inthis manner, the lift strap 62 forms a loop of material at its end withthe mandrel held tightly inside of the resulting loop. However, in analternate embodiment, the strap locking bar 66 is comprised of a seriesof pins 68, for example three parallel pins that are each mated at theirends to the inner facing surfaces of parallel first and second endplates 70, such that the axes of the pins are perpendicular to theparallel surfaces of the plates. The end of the lift strap 62 is wrappedaround one of the pins and secured back onto itself using bartackstitching 72 or other securing method, while the adjoining portion ofthe lift strap is woven around and through the remaining series of pins.

The lift strap 62 exits this labyrinth of pins that comprise the straplocking bar 66 at a point after which the strap has been at leastpartially woven around or past each of the individual pins, making somecontact with the outer surface of each pin. The purpose of weaving thelift strap 62 around each in a series of pins 68 is to provide frictionbetween the lift strap 62 and the outer surface of each pin 68. By doingso, if the split lift drum 2 is ever in a position where the lift strap62 is completely unwound from the work surface of the split lift drum 2while an active load is suspended from the free end of the lift strap62, then the entire force of the active load is not being supportedsolely by the stitching or other securing mechanism used to secure thestrap 62 back on to itself. The friction provided by the lift strap 62woven around and through the series of pins 68 serves to lessen the loadand active stresses that would otherwise be placed on the stitching.

Coated Lift Strap & Protective Sleeve

Referring to FIGS. 9 and 10, the lift strap 962 used with the straplocking bar 66, the lift drum and overhead lift 907 may be any type ofstrap that is approved for medical lifting of patients or other loads.For example, the lift strap may be woven textile, such as wovenpolyester or nylon as is commonly used with patient lifts. In alternateembodiments, the lift strap may be a woven textile strap that has beenchemically treated and/or polymer-coated to provide increased infectioncontrol to the lift system and lift strap 962. A polymer coated liftstrap for infection control may comprise a base lift strap, such as awoven polyester textile strap, any number of antibacterial chemicaltreatments applied to the base lift strap to impregnate the chemicaltreatment within the individual fibers of the woven base lift strap, andany number of polymer coatings applied thereafter that encase thechemical treated woven base lift strap in one or more layers thereof.

In one embodiment, an infection control lift strap comprises a wovenpolyester base lift strap that has been treated with a chemical, such asAegis antimicrobial coating treatment or Maedical i-LiNK advancedantimicrobial treatments developed by Devan Chemicals N.V., which, forexample, chemically bonds to the fibers of the woven base lift strap andcreates a life-long protection against various microorganisms andbacteria, including Clostridium Difficile, more commonly referred to asC. Diff. The embodiment of this lift strap 962 could additionallyinclude a disinfectant-safe coating 950 applied over the chemicallytreated base lift strap, such that disinfectants can be regularly usedon the lift strap 962 without damaging or altering the chemical bondthat exists between the chemical treatment and the base lift strap.

In another embodiment, an infection control lift strap 962 may be awoven textile lift strap that has one or more layers of a non-porouswipeable polymer over-coating, such as the BioThane Coated Webbing brandcoated strap products developed by BioPlastics Company Inc. In yetanother embodiment, an infection control lift strap may be a solid strapthat is flexible, non-porous, and chemically wipeable, wherein the liftstrap 962 is neither a woven strap nor needs any over-coating to bewipeable with chlorinated bleach or other sanitization products.

In still other embodiments, the lift strap 962 can include anycombination of a solid base strap or a woven textile base strap, one ormore chemical treatments applied thereto, and/or one or more outerover-coating layers that encapsulate the lift strap therein (e.g., thebase strap and the chemical treatment applied) and that are impermeableto chlorinated bleach or other harsh cleaning or disinfection solutions.For example, an overcoating 950 could include coatings of eitherpolyurethane, polyvinyl chloride (PVC), or other such polymers thatcompletely seal the base strap therein and are able to be wiped downwith chlorinated bleach or other such harsh antibacterial or cleaningsolutions. The over-coating 950 used with a woven lift strap 962 wouldfill in all the small crevices and spaces between the fibers of thewoven lift strap and provide a continuous sealed outer surface withoutany crevices or spaces in which chlorine crystals could form whenchlorinated bleach used to clean the lift strap dries. Any such crystalswould form on the outer surface of the over-coating 950 and not causedamage to the base lift strap 962.

In addition, a disposable or washable flexible protective sleeve 902could be used with the lift strap 962 to increase infection controlproperties with regard to the overhead lift 907, the lift strap 962, andthe inner workings of the overhead lifts 907. Such a protective sleeve902 would serve to prevent bacteria or other contaminants from everreaching the lift strap 962 while the sleeve 902 is in place.

In one embodiment, a protective sleeve 902 comprises a flexibleelongated tubular polymer sleeve, having double sided adhesive strips904 disposed at both ends thereof around the full circumference of theopenings of the sleeve. One side of the double sided adhesive tape 904would be secured to an inner surface of the outer sleeve at the openends thereof and have a removable backing paper disposed on the oppositeside of the double sided adhesive strip 904. The sleeve 902 could beslid over the free hanging end 908 of the lift strap 962 in an overheadlift 907. A first end of the protective sleeve 910 is slid over the freeend of the lift strap 908, such that the lift strap 962 is locatedinside of the tubular sleeve 902 and the first end 910 is the uppermostend of the sleeve relative to the hanging lift strap 962. The first endof the sleeve 910 is then positioned such that it is located adjacentthe housing 957 of the overhead lift 907. The removable backing stripson the adhesive tape 904 located at the upper end of the protectivesleeve 902 are then removed, and the upper end of the protective sleeve902 can then be sealingly secured to the lift housing 957 around theslot 959 in the housing from which the lift strap 962 protrudes.

In one embodiment the second (i.e., lower) end of the protective sleeveis open. In another embodiment, the lower end of the protective sleeve912 is secured by its adhesive tape to either the solid lifting fixtureor clip secured to the free end of the lift strap 908, or to a sling bar973 that is secured below the lifting fixture. With the upper end of theprotective sleeve 910 sealingly secured to the lift housing 957 and thelower end of the protective sleeve 912 sealingly secured to the liftingfixture, or sling bar 973, the lift strap 962 is fully sealed within theprotective sleeve 902. Thus, no bacteria or other contaminants are ableto gain access to the lift strap. With the use of a protective sleeve902 as disclosed herein, the frequency with which the lift strap 902needs to be cleaned or sanitized is significantly reduced, or the needto clean the lift strap 962 is altogether eliminated. In this manner,the useable life of the lift strap 962 can be significantly extended.

A protective sleeve 902 for use with the lift strap as disclosed hereinis thin and flexible and will easily bunch and straighten out along itslength as the lift strap 962 is either wound up on the lift drum in thelift housing 957, or paid out therefrom. The lift strap 962 can bedisposable and made from any polymer, especially any polymer that whenextruded into a thin tubular sleeve is impermeable to bacteria and othermicroscopic contaminants. After use, the disposable protective sleeve902 is simply removed and discarded and a new sterile protective sleeve902 can be installed in its place. In alternate embodiments, theprotective sleeve 902 can be a washable textile-based sleeve, or atextile-based sleeve having a sealed outer surface, both of which arecapable of being washed, sterilized, and reused.

What is claimed is:
 1. A lift strap for use with a patient lift system,comprising: a base lift strap comprising a textile; and at least onechemical treatment applied on the base lift strap operative to provideinfection control.
 2. The lift strap of claim 1, wherein the textile iswoven and comprises at least one of (i) polyester and (ii) nylon.
 3. Thelift strap of claim 1, wherein the textile is woven and has individualfibers that are impregnated with an antibacterial chemical treatment. 4.The lift strap of claim 3, further comprising at least one additionalpolymer coating over the antibacterial chemically treated impregnatedfibers.
 5. The lift strap of claim 4, wherein the chemical treatment isone of (i) an Aegis antimicrobial treatment or (ii) Maedical i-LiNKadvance antimicrobial treatment, and wherein the chemical treatmentchemically bonds to the impregnated fibers, thereby creating life-longprotection against microorganisms and bacteria.
 6. The lift strap ofclaim 2, wherein the woven textile has at least one non-porous wipeablepolymer over-coating.
 7. The lift strap of claim 1, further comprisingat least one outer over-coating layer that seals the base lift strap andthe at least one chemical treatment, wherein the base lift strap is oneof (i) solid or (ii) woven.
 8. The lift strap of claim 6, wherein theover-coating comprises at least one of (i) polyurethane or (ii)polyvinyl chloride (PVC) and wherein the over-coating seals the baselift strap such that it is impermeable to chlorinated bleach.
 9. Thelift strap of claim 6, wherein the over-coating fills in small crevicesand spaces between fibers of the woven lift strap and provides acontinuous sealed outer surface without any crevices or spaces in whichchlorine crystals could form when chlorinated bleach used to clean thelift strap dries.
 10. The lift strap of claim 1, wherein the base liftstrap comprises: a first end coupled to a two-piece lift drum of a lifthousing; and a second end configured to be coupled to a sling bar. 11.The lift strap of claim 10, wherein the lift strap is configured to bewound around an outer work surface of the lift drum.
 12. The lift strapof claim 10, wherein the first end of the lift strap is configured to beslidably disengaged from the lift system.
 13. The lift strap of claim10, further comprising a protective sleeve covering the base lift strap.14. A patient lift system, comprising: a lift housing; a liftingmechanism within the housing; a base lift strap having a first endcoupled to the lifting mechanism and a second end coupled to a slingbar; and a protective sleeve covering portions of the base lift strapextending from the lift housing, wherein the protective sleeve has afirst end and a second end and is operative to provide infectioncontrol.
 15. The patient lift system of claim 14, wherein the protectivesleeve is disposable and washable.
 16. The patient lift system of claim14, wherein the protective sleeve comprises a flexible elongated polymertube having a double sided adhesive strip at both the first end and thesecond end of the protective sleeve.
 17. The patient lift system ofclaim 14, wherein the second end of the protective sleeve is open. 18.The patient lift system of claim 14, wherein the first end of theprotective sleeve is sealingly connected to the lift housing around aslot in the lift housing from which base lift strap protrudes.
 19. Thepatient lift system of claim 16, wherein a first side of the doublesided adhesive strips is secured to an inner surface of correspondingones of the first and second ends of the protective sleeve and thedouble sided adhesive strips have a removable backing paper disposed ona second side of the double sided adhesive strip.
 20. The patient liftsystem of claim 14, wherein the second end of the protective sleeve issecured by its adhesive strip to one of (i) a solid lifting fixturesecured to the second end of the base lift strap, or (ii) the sling bar.